1. Field of the Invention
The present invention relates to the fabrication of integrated circuit devices, and more particularly, to a method of avoiding a tungsten tunnel due to BP-TEOS interlayer tunneling in the fabrication of integrated circuits.
2. Description of the Prior Art
In the fabrication of integrated circuit devices, borophospho-tetraethoxysilane (BP-TEOS) is often used as an interlayer dielectric material. However, it is possible that a short could develop between contacts caused by abnormal BP-TEOS film. It has been found that a tunnel may open up in the BP-TEOS film between two contact openings, causing a short.
U.S. Pat. No. 5,296,400 to Park et al shows a method of forming a contact pad using borophosphosilicate glass (BPSG) or borophospho-tetraethoxysilane (BP-TEOS). U.S. Pat. No. 5,340,774 to Yen shows a method of planarization of BPSG or BPTEOS using an etch. Neither of these references mentions the problem of an interlayer tunnel.